1. Field of the Invention
The present invention relates to an electronic circuit device for which a high heat radiating or dissipating ability is required and a method of fabricating such an electronic circuit device, and more particularly to the structure of a package of an electronic circuit device and a method for fabrication of the same.
2. Description of Related Art
Prior art will be described referring to FIGS. 4 and 5.
FIG. 4 shows the setting structure of a rectifier for vehicle disclosed by JP-Y-6-9577. A frame member 16 and a substrate 12 are fixed through screws 20 onto a surface of a pedestal or the like (not shown) on which the rectifier is to be installed. Thereby, a structure having an excellent productivity and a satisfactory heat dissipating efficiency is provided. In this structure, no radiating fin is used. There instead, heat dissipation is mainly made from a surface of the rectifier to be installed on the pedestal or the like (or a surface of the substrate 12 having no parts mounted thereon).
On the other hand, the conventional electronic circuit device using a radiating fin is shown in FIG. 5. In the figure, reference numeral 21 denotes a metal substrate, numeral 22 denotes a case, numeral 23 denotes a mold resin, numeral 24 denotes a portion of the case 22 abutting against the substrate 21, numeral 25 denotes a connector, numeral 27 denotes an installation surface of the electronic circuit device, numeral 28 denotes an end face of the case 22, and numeral 29 denotes a radiating fin. In such conventional electronic circuit device with radiating fin, a surface of the metal substrate having no parts mounted thereon is brought into contact with the bottom of the case, thereby improving the heat dissipation from the radiating fin.
However, in the setting structure of the rectifier for this vehicle shown in FIG. 4, heat dissipation is mainly made from the surface of the substrate 12 having no parts mounted thereon, that is, the heat dissipation from a surface of the substrate having parts mounted thereon is not taken into consideration.
In the electronic circuit device shown in FIG. 5, the dissipation of heat thermally conducted from the surface of the metal substrate 21 having no parts mounted thereon and radiated from the radiating fin 29 is satisfactory but the heat dissipation from the installation surface of the electronic circuit device (or a surface of the metal substrate 21 having parts mounted thereon) is not particularly taken into consideration.